Artificial teeth

ABSTRACT

A set of artificial teeth for a denture comprises a maxillary unit and a mandibular unit. When set up in lingualised occlusion, at least one of following occurs: the palatal cusp of the upper  4  ( 1 ) fits into the distal fossa of the lower  4  ( 6 ), the palatal cusp of the upper  5  ( 2 ) fits into the distal fossa of the lower  5  ( 7 ), the mesial palatal cusp of the upper  6  ( 3 ) fits into the central fossa of the lower  6  ( 8 ), the distal palatal cusp of the upper  6  ( 4 ) fits onto the marginal ridge of the lower  6  ( 9 ) and the mesial palatal cusp of the upper  7  ( 5 ) fits into the central fossa of the lower  7  ( 10 ). The buccal cusps of the lower teeth are out of contact with the upper teeth, such that the cusp/fossa dimensions and relationships of the teeth concerned enable the occlusal scheme for the teeth to be changed from lingualised to balanced occlusion simply by softening the wax or resin under the upper posterior teeth and rotating the upper buccal cusps downwards around the said palatal cusps on the upper teeth with such palatal cusps still substantially remaining within the centric stops of the lowers.

FIELD OF THE INVENTION

The present invention relates to a set of artificial teeth, a method forthe production of a denture utilising the set of artificial teeth.

BACKGROUND OF THE INVENTION

Dentures are prosthetic devices constructed to replace missing teeth.They are supported by the surrounding soft and hard tissues of the oralcavity. Complete dentures replace all of the teeth in the upper and/orthe lower jaw, whereas partial dentures only replace some of the teethin the jaw concerned. For example, partial dentures may replace one ormore front teeth and/or one or more of the posterior teeth.

In natural human dentition, the tooth distribution in each quadrant ofthe mouth consists of three front teeth, and four or five posteriorteeth including two pre-molars and two or three molars. Whenconstructing a complete denture either three or more typically fourposterior teeth are used. When constructing a partial denture, thenumber of teeth used depends on factors such as the number of remainingnatural teeth and the space available. The third molar tooth is notalways present in the natural human dentition, and is not usuallyincluded in dentures.

The teeth of the natural human dentition are frequently referred to bydentists, clinicians, and dental technicians using the Palmer notation.The Palmer notation is a system used to associate information with aspecific tooth, and is a simple system in that it does not necessitatedifferentiating between left and right of the mouth. Although supposedlysuperseded by the FDI World Dental Federation notation, it continues tobe the preferred method used by many practitioners in the United Kingdomand in other countries.

In the Palmer system, the permanent adult teeth are numbered from 1 to8, the numbering indicating the position from the midline. The Palmernotation additionally uses a symbol (┘└┐┌) designating in which quadrantthe tooth is found. Hence the left and right maxillary central incisorshave the same number, “1”, but the right one has the symbol, “┘”,underneath it, while the left one has the symbol, “└”.

The Palmer notation consists of a symbol (┘└┐┌) designating in whichquadrant the tooth is found and a number indicating the position fromthe midline. Adult teeth are numbered 1 to 8. Hence the left and rightmaxillary central incisor would have the same number, “1”, but the rightone would have the symbol, “┘”, underneath it, while the left one wouldhave, “└”. It is also commonplace to refer to the maxillary teeth as theupper teeth, and the mandibular teeth as the lower teeth, in combinationwith the number given under the Palmer system.

Accordingly, the maxillary teeth of the adult human dentition may bereferred to as follows: first and second incisors=upper 1 and upper 2;canine=upper 3; first and second premolars=upper 4 and upper 5; first,second, and third molars=upper 6, upper 7, and upper 8. Similarly, themandibular teeth of the adult human dentition may be referred to asfollows: first and second incisors=lower 1 and lower 2; canine=lower 3;first and second premolars=lower 4 and lower 5; first, second, and thirdmolars=lower 6, lower 7, and lower 8.

Dentures should be retentive, comfortable and provide support for thecheeks and lips. They should allow effective mastication, acceptableaesthetics, clear phonetics, and contribute to the wearer's confidenceand self-esteem.

The construction of complete dentures involves a number of clinical andlaboratory stages that may include some or all of the following:

Primary impressions—these are the initial impressions of the patient'sedentulous arches recorded in the surgery. The dental technician wouldthen cast stone or plaster models from these impressions and constructspecial trays that are specifically adapted to the individual patient'smouth.

Secondary impressions—the special trays are then used to record accurateand more detailed impressions.

Jaw registration—the dental technician will construct wax rims on modelsproduced from these initial impressions, which are representative of theposition of the patient's original teeth. The rims are modified in thesurgery to reflect the current situation or desired clinical outcome andwill provide guidance to the technician for the set-up on wax of bothanterior and posterior teeth on a trial denture. The anterior teeth areset up using anatomical markers, in order to achieve the desiredaesthetic result. The posterior teeth are then set up in occlusion onthe wax, in order to provide the patient with an acceptable bite andadequate function.

Denture try-in—the artificial teeth having been set up on wax by thetechnician, the clinician will try the dentures in the patient's mouthto check the appearance, phonetics, and function.

Denture fit—once the try-in has proved acceptable, the trial denturesare processed and finished and the clinician finally fits the dentures.

Modern technology has allowed many of these stages to become digitisedand a modified workflow has evolved and will continue to be developed:

Impressions—primary impressions and secondary impressions may still berecorded and the laboratory will digitally scan the model and theadjusted wax rims. This will record the anatomical detail of the jawsand the desired occlusal plane. In some cases, this detail may bescanned directly at the chairside and transmitted to the dentallaboratory.

Reference Points—within the denture design software Reference Points canbe set to reflect the anatomical landmarks, in order to guide the set-upof the denture teeth.

Denture Design—the software allows the design of the denture base toensure optimal coverage of the soft tissues.

Selection of Teeth—this is done virtually and the teeth are set up inthe desired occlusal scheme within the denture design software. Wherethis takes place, the teeth are not set—up on wax and the change frombalanced to lingualised occlusion or vice versa may therefore beperformed digitally. In this case the rotation of the upper buccal cuspsas described and claimed below may take place digitally, rather than bysoftening the wax.

Digital Manufacture of Dentures—after the denture design has beenfine-tuned and confirmed, the dentures are constructed. This may be doneby a milling machine, 3D printing or some other means of production.

The challenge faced by the dental technician is to establish afunctional occlusion for the patient using artificial posterior teeth,as he may have little or no information about the patient's naturalteeth and their occlusal scheme. Occlusion is defined as therelationship of the maxillary and mandibular teeth when they are infunctional contact during mandibular activity.

Traditionally the two most common types of posterior tooth set up arelingualised occlusion and balanced occlusion.

In lingualised occlusion, the palatal cusps of the upper (maxillary)teeth engage in the central fossae of the lower (mandibular) teeth, withthe buccal cusps of the upper teeth tilted at such an angle so that innormal function they never come into contact with the lower teeth. Inlingualised occlusion, the palatal cusps of the upper posteriors makecontact in centric relation in the central fossae of the lowerposteriors. The buccal cusps are out of contact; however the lingualcusps remain in contact in centric, working (mandible moving to thecheek) and balancing (opposite side of mandible moving to the tongue)movements.

In previous examples of teeth designed for lingualised occlusion, thelower teeth frequently have cusps with a very low incisal angle, or havefewer or smaller cusps, or the occluding surfaces may have a saucershape in which the upper palatal cusps move.

The advantages of lingualised occlusion in comparison with otherocclusion schemes are:

-   -   Reduced lateral stresses and dislodging forces    -   Stability    -   Ease of set-up as centric limited to the centric stop in the        fossa    -   Excellent aesthetics with buccal cusp form retained    -   Enhanced functionality with good penetration of the food bolus    -   Vertical forces in the centric position are more in line with        the alveolar ridge

In the scheme of balanced occlusion when in full contact, the palatalcusps of the upper (maxillary) teeth are in contact with the fossae ofthe lower (mandibular) teeth, and the buccal cusps of the lower teethare in contact with the fossae of the upper teeth in centric occlusion.At rest, the buccal cusps of the upper teeth and the lingual cusps ofthe lower teeth are not normally in contact with the opposing teeth, butdo come into contact during excursive movements.

On the working side, the buccal cusps of the upper posterior teethsmoothly glide into contact with the buccal cusps of the lower denture.On the balancing side, the buccal cusps of the lower posterior teethmaintain contact with the palatal cusps of the respective upper dentureteeth. This bilateral balanced occlusion maintains contact between theupper and lower dentures and prevents tipping of the denture, therebyenhancing stability.

The advantages of balanced occlusion in comparison with other occlusionschemes are:

-   -   Distribution of load    -   Stability    -   Reduced trauma    -   Functional movement    -   Masticatory efficiency    -   Comfort

There are different theories as to why one scheme is better or worsethan the other, and many previous designs of teeth can be set up by askilled technician to be used in either format. However, in such teeth,the set-up has to be made differently for each format and, in order tochange from a balanced occlusal concept to a lingualised occlusalconcept, or vice versa, some or all of the teeth have to be newly set upon the wax base or the occlusion/cusps reshaped by grinding to conformto the new scheme.

For example, WO 2004/096077 describes a set of teeth designedexclusively for lingualised occlusion. Similarly, WO 2007/071980describes a set of artificial teeth that can be set up in balancedocclusion, bucco-lingually and/or antero-posteriorly, in which theworking cusp spacings of the maxillary posterior teeth are substantiallythe same as those of the mandibular posterior teeth. In order to set theteeth up in lingualised occlusion, an additional spacer is required.Furthermore, US 2005/0095559 (Monkmeyer) describes a set of artificialteeth in which the stamp cusps of each tooth rest on three points of itsantagonist fossa in centric relationship. However, there is no provisionin any of the documents for a single set of artificial teeth that can besimply changed between occlusal schemes, particularly between a balancedand lingualised occlusion.

Similarly, US 2004/0137407 (Ivoclar Vivadent) describes a kit comprisingtwo separate sets of posterior artificial teeth used for the productionof dentures—one for lingualized occlusion and one with zero degreemonoplane occlusion surfaces (i.e. for balanced occlusion). This is inkeeping with the widely held view of dental technicians that separatesets of artificial teeth are required for different occlusal schemes,the possibility of artificial teeth being adjustable between two typesof occlusion not being envisaged.

Therefore, there is a demand for a set of artificial teeth that is setup in either balanced or lingualised occlusion, and can be simply andreadily changed to the alternate occlusal scheme, while maintaining therelative positions of the teeth concerned.

The present invention seeks to design an improved set of artificialteeth which overcomes the problems associated with existing artificialdenture teeth as described above by providing a design of artificialdenture teeth which are set up in either balanced or lingualisedocclusal schemes and can be readily changed to the alternate occlusalscheme.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a set of artificial teethcomprising a maxillary unit and a mandibular unit in which, when set upin lingualised occlusion, at least one of following occurs: the palatalcusp of the upper 4 (1) fits into the distal fossa of the lower 4 (6),the palatal cusp of the upper 5 (2) fits into the distal fossa of thelower 5 (7), the mesial palatal cusp of the upper 6 (3) fits into thecentral fossa of the lower 6 (8), the distal palatal cusp of the upper 6(4) fits onto the marginal ridge of the lower 6 (9) and the mesialpalatal cusp of the upper 7 (5) fits into the central fossa of the lower7 (10), and wherein the buccal cusps of the lower teeth are out ofcontact with the upper teeth, such that the cusp/fossa dimensions andrelationships of the teeth concerned enable the occlusal scheme for theteeth to be changed from lingualised to balanced occlusion simply bysoftening the wax or resin under the upper posterior teeth and rotatingthe upper buccal cusps downwards around the said palatal cusps on theupper teeth with such palatal cusps still remaining within the centricstops of the lowers.

In another aspect, the present invention provides a set of artificialteeth comprising a maxillary unit and a mandibular unit in which, whenset up in balanced occlusion, at least one of the following occurs: thepalatal cusp of the upper 4 (1) fits into the distal fossa of the lower4 (6), the palatal cusp of the upper 5 (2) fits into the distal fossa ofthe lower 5 (7), the mesial palatal cusp of the upper 6 (3) fits intothe central fossa of the lower 6 (8), the distal palatal cusp of theupper 6 (4) fits onto the marginal ridge of the lower 6 (9), and themesial palatal cusp of the upper 7 (5) fits into the central fossa ofthe lower 7 (10), and wherein at least one of the buccal cusps of thelower teeth are in contact with the upper teeth, such that thecusp/fossa dimensions and relationships of the teeth concerned enablethe occlusal scheme for the teeth to be changed from balanced tolingualised occlusion simply by softening the wax or resin under theupper posterior teeth and rotating the upper buccal cusps upwards aroundthe said palatal cusps on the upper teeth with such palatal cusps stillremaining within the centric stops of the lowers.

The artificial denture teeth of the invention present clearly definedupper palatal stamp cusps on one or more of the upper teeth and centricstops on the occluding (biting) surfaces of one or more of the lowerteeth. The design of the artificial denture teeth is particularly ofmerit for complete dentures. This design enables the denture teeth to beeasily set up in a number of different occlusal schemes includinglingualised, balanced, cross bite, and edge to edge occlusal schemes.However, the present invention specifically relates to sets ofartificial teeth in which the teeth are set up in either balanced orlingualised occlusal schemes and can be readily switched between the twoschemes.

The sets of artificial teeth according to the present invention may beset up in either balanced or lingualised occlusal schemes, and if one ofthese schemes is chosen and proves not to be acceptable in a particularclinical case, then the dental technician can readily change to thealternate occlusal scheme. This is achieved by softening the wax orresin under the upper posterior teeth and rotating the teeth asdescribed to bring them into the alternate occlusal scheme. The toothshape allows a simple rotation around one or more stamp cusps of theupper posterior teeth which still remain within their occlusal stops inthe opposing lowers, thereby maintaining the relative positions of theteeth concerned, and making changing the occlusal scheme easy to carryout.

Preferably, the change to the alternate occlusal scheme is achieved bysoftening the wax or resin under the upper posterior teeth and simplyrotating the upper buccal cusps around the upper palatal stamp cusp orcusps. In the case of changing from a lingualised to a balanced occlusalscheme, the upper buccal cusps are rotated downwards. In the case ofchanging from a balanced to a lingualised scheme, the upper buccal cuspsare rotated upwards. Although in the conventional approach, this isachieved by simply softening the wax or resin and rotating the teeth, indigitally constructed dentures this is achieved by making adjustmentswithin the software.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the occlusal surface of upper posterior teeth embodying theinvention.

FIG. 2 shows the occlusal surface of lower posterior teeth embodying theinvention.

FIG. 3 shows a cross-sectional view of a single upper tooth and a singlelower tooth when set up and engaged in lingualised occlusion.

FIG. 4 shows a cross-sectional view of a single upper tooth and a singlelower tooth when set up and engaged in balanced occlusion.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a set of artificial teeth comprising amaxillary unit and a mandibular unit in which, when set up inlingualised occlusion, at least one of following occurs: the palatalcusp of the upper 4 (1) fits into the distal fossa of the lower 4 (6),the palatal cusp of the upper 5 (2) fits into the distal fossa of thelower 5 (7), the mesial palatal cusp of the upper 6 (3) fits into thecentral fossa of the lower 6 (8), the distal palatal cusp of the upper 6(4) fits onto the marginal ridge of the lower 6 (9) and the mesialpalatal cusp of the upper 7 (5) fits into the central fossa of the lower7 (10), and wherein the buccal cusps of the lower teeth are out ofcontact with the upper teeth, such that the cusp/fossa dimensions andrelationships of the teeth concerned enable the occlusal scheme for theteeth to be changed from lingualised to balanced occlusion simply bysoftening the wax or resin under the upper posterior teeth and rotatingthe upper buccal cusps downwards around the said palatal cusps on theupper teeth with such palatal cusps still remaining within the centricstops of the lowers.

The present invention also provides a set of artificial teeth comprisinga maxillary unit and a mandibular unit in which, when set up in balancedocclusion, at least one of the following occurs: the palatal cusp of theupper 4 (1) fits into the distal fossa of the lower 4 (6), the palatalcusp of the upper 5 (2) fits into the distal fossa of the lower 5 (7),the mesial palatal cusp of the upper 6 (3) fits into the central fossaof the lower 6 (8), the distal palatal cusp of the upper 6 (4) fits ontothe marginal ridge of the lower 6 (9), and the mesial palatal cusp ofthe upper 7 (5) fits into the central fossa of the lower 7 (10), andwherein at least one of the buccal cusps of the lower teeth is incontact with the upper teeth, such that the cusp/fossa dimensions andrelationships of the teeth concerned enable the occlusal scheme for theteeth to be changed from balanced to lingualised occlusion simply bysoftening the wax or resin under the upper posterior teeth and rotatingthe upper buccal cusps upwards around the said palatal cusps on theupper teeth with such palatal cusps still remaining within the centricstops of the lowers.

The following definitions shall apply throughout the specification andthe appended claims.

Within the context of the present specification, the term “comprises” istaken to mean “includes” or “contains”, i.e. other integers or featuresmay be present, whereas the term “consists of” is taken to mean“consists exclusively of”.

Within the present specification, the term “about” means plus or minus20%; more preferably plus or minus 10%; even more preferably plus orminus 5%; most preferably plus or minus 2%.

Within the present specification, the term “denture” means a prostheticdevice constructed to replace missing teeth; a denture consists of adenture base that is supported by the soft and hard tissues of the oralcavity, and artificial denture teeth that restore aesthetics andfunction for a patient.

Within the present specification, the term “stamp cusp” means a toothcusp that, when the tooth is in occlusion, fits in the fossa of theantagonist tooth in a mortar-and-pestle fashion.

Within the present specification, the term “centric stop” means a stablepoint of contact between occluded maxillary and mandibular teeth.Centric stops are located in the central fossa, marginal ridges andbuccal and lingual cusps of posterior teeth.

As described above, in the set of artificial teeth set up in lingualisedocclusion according to the present invention, at least one of thefollowing occurs: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10).

Preferably, in the set of artificial teeth set up in lingualisedocclusion according to the present invention, at least two of thefollowing occur: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10).

More preferably, in the set of artificial teeth set up in lingualisedocclusion according to the present invention, at least three of thefollowing occur: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10).

More particularly preferably, in the set of artificial teeth set up inlingualised occlusion according to the present invention, at least fourof the following occur: the palatal cusp of the upper 4 (1) fits intothe distal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10).

Most preferably, in the set of artificial teeth set up in lingualisedocclusion according to the present invention, all of the followingoccur: the palatal cusp of the upper 4 (1) fits into the distal fossa ofthe lower 4 (6), the palatal cusp of the upper 5 (2) fits into thedistal fossa of the lower 5 (7), the mesial palatal cusp of the upper 6(3) fits into the central fossa of the lower 6 (8), the distal palatalcusp of the upper 6 (4) fits onto the marginal ridge of the lower 6 (9)and the mesial palatal cusp of the upper 7 (5) fits into the centralfossa of the lower 7 (10).

In a preferred embodiment, the present invention provides a set ofartificial teeth set up in lingualised occlusion as described above,wherein the cusp/fossa dimensions and relationships of the teethconcerned enable the occlusal scheme for the teeth to be changed fromlingualised to balanced occlusion. The change from lingualised tobalanced occlusion is preferably achieved simply by softening the wax orresin under the upper posterior teeth and rotating the upper buccalcusps downwards around the palatal stamp cusps on the upper teeth withsuch stamp cusps still substantially remaining within the centric stopsof the lowers.

As described above, in the set of artificial teeth set up in balancedocclusion according to the present invention, at least one of thefollowing occurs: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9), and the mesial palatal cusp of the upper 7 (5) fitsinto the central fossa of the lower 7 (10).

Preferably, in the set of artificial teeth set up in balanced occlusionaccording to the present invention, at least two of the following occur:the palatal cusp of the upper 4 (1) fits into the distal fossa of thelower 4 (6), the palatal cusp of the upper 5 (2) fits into the distalfossa of the lower 5 (7), the mesial palatal cusp of the upper 6 (3)fits into the central fossa of the lower 6 (8), the distal palatal cuspof the upper 6 (4) fits onto the marginal ridge of the lower 6 (9), andthe mesial palatal cusp of the upper 7 (5) fits into the central fossaof the lower 7 (10).

More preferably, in the set of artificial teeth set up in balancedocclusion according to the present invention, at least three of thefollowing occur: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9), and the mesial palatal cusp of the upper 7 (5) fitsinto the central fossa of the lower 7 (10).

More particularly preferably, in the set of artificial teeth set up inbalanced occlusion according to the present invention, at least four ofthe following occur: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9), and the mesial palatal cusp of the upper 7 (5) fitsinto the central fossa of the lower 7 (10).

Most preferably, in the set of artificial teeth set up in balancedocclusion according to the present invention, all of the followingoccur: the palatal cusp of the upper 4 (1) fits into the distal fossa ofthe lower 4 (6), the palatal cusp of the upper 5 (2) fits into thedistal fossa of the lower 5 (7), the mesial palatal cusp of the upper 6(3) fits into the central fossa of the lower 6 (8), the distal palatalcusp of the upper 6 (4) fits onto the marginal ridge of the lower 6 (9),and the mesial palatal cusp of the upper 7 (5) fits into the centralfossa of the lower 7 (10).

As described above, in the set of artificial teeth set up in balancedocclusion according to the present invention, at least some of thebuccal cusps of the lower teeth are in contact with the upper teeth.Preferably, in the set of artificial teeth set up in balanced occlusionaccording to the present invention, at least one buccal cusp of thelower teeth is in contact with the upper teeth. More preferably, atleast two, at least three, or at least four buccal cusps of the lowerteeth are in contact with the upper teeth. Most preferably, all of thebuccal cusps of the lower teeth of the set of artificial teeth are incontact with the upper teeth. In centric occlusion, the buccal cusps ofthe lower teeth are in contact with the central fossae of the upperposterior teeth. In excursive movements the buccal cusps of the lowerposterior teeth remain substantially in contact with the upper teeth,smoothly moving to contact with the buccal cusps of the upper teeth onthe working side. Conversely the buccal cusps remain substantially incontact with the upper teeth, smoothly moving to contact with the buccalcusps of the upper teeth on the balancing side.

In a preferred embodiment, the present invention provides a set ofartificial teeth set up in balanced occlusion as described above,wherein the cusp/fossa dimensions and relationships of the teethconcerned enable the occlusal scheme for the teeth to be changed frombalanced to lingualised occlusion. The change from balanced tolingualised occlusion is preferably achieved simply by softening the waxor resin under the upper posterior teeth and rotating the upper buccalcusps upwards around the palatal stamp cusps on the upper teeth withsuch stamp cusps still remaining within the centric stops of the lowers.

As described above, the set of artificial teeth according to theinvention comprises a maxillary unit and a mandibular unit. Typically,the maxillary unit and the mandibular unit of the set of artificialteeth may be regarded as a maxillary unit and mandibular unit pair. In apreferred embodiment, the set of artificial teeth comprises twomaxillary unit and mandibular unit pairs, each unit designed forarrangement in a respective quadrant of the patient's mouth.

The maxillary unit typically comprises a wax or resin base supporting atleast three, or at least four maxillary posterior teeth. In onepreferred embodiment, the maxillary unit comprises a wax or resin basesupporting three maxillary posterior teeth. In this embodiment, themaxillary unit preferably comprises a wax or resin base supporting firstand second maxillary pre-molar teeth and a single maxillary molar tooth.More preferably, the maxillary unit comprises a wax or resin basesupporting four maxillary posterior teeth. In a particularly preferredembodiment, the maxillary unit comprises a wax or resin base supportingfirst and second maxillary pre-molar teeth and first and secondmaxillary molar teeth. These teeth are referred to as the upper 4, upper5, upper 6, and upper 7. Accordingly, the maxillary unit preferablycomprises a wax or resin base and at least three of the upper 4, upper5, upper 6, and upper 7 teeth. Preferably, the maxillary unit comprisesa wax or resin base and at least the upper 4, upper 5, and upper 6teeth. More preferably, the maxillary unit comprises a wax or resin baseand all four of the upper 4, upper 5, upper 6, and upper 7 teeth.

The mandibular unit typically comprises a wax base supporting at leastthree, or at least four mandibular posterior teeth. In one preferredembodiment, the mandibular unit comprises a wax or resin base supportingthree mandibular posterior teeth. In this embodiment, the mandibularunit preferably comprises a wax or resin base supporting first andsecond mandibular pre-molar teeth and a single mandibular molar tooth.More preferably, the mandibular unit comprises a wax or resin basesupporting four mandibular posterior teeth. In a particularly preferredembodiment, the mandibular unit comprises a wax or resin base supportingfirst and second mandibular pre-molar teeth and first and secondmandibular molar teeth. These teeth are referred to as the lower 4,lower 5, lower 6, and lower 7. Accordingly, the mandibular unitpreferably comprises a wax or resin base and at least three of the lower4, lower 5, lower 6, and lower 7 teeth. Preferably, the maxillary unitcomprises a wax or resin base and at least the lower 4, lower 5, andlower 6 teeth. More preferably, the mandibular unit comprises a wax orresin base and all four of the lower 4, lower 5, lower 6, and lower 7teeth.

In a preferred embodiment in which the maxillary unit comprises a wax orresin base supporting four maxillary posterior teeth, the width of theset of four upper or maxillary posterior teeth is from about 20 mm toabout 60 mm. More preferably, the width of the set of four upperposterior teeth is between about 25 mm and about 40 mm. In a preferredembodiment in which the mandibular unit comprises a wax or resin basesupporting four mandibular posterior teeth, the width of the set of fourlower posterior teeth is from about 20 mm to about 65 mm. Morepreferably, the width of the set of four lower posterior teeth isbetween about 26 mm and about 44 mm.

In a preferred embodiment, the buccal cusp angles of the set ofartificial teeth are typically in the range of between about 10° andabout 40°. In another preferred embodiment, the height of the palatalcusps and/or buccal cusps is typically between about 1 mm and about 5mm.

The sets of artificial teeth of the present invention may be produced byany suitable method known to the skilled person such as compressionmoulding, injection moulding, transfer moulding, milling or 3D printing.

Individual teeth for use in the sets of artificial teeth of the presentinvention may be formed from any suitable material known to the skilledperson. Preferably, the individual teeth are formed from one or moresynthetic resins, such as acrylates, which may when so required befilled with organic or inorganic fillers in order to improve theirproperties, or from porcelain or other inorganic material.

The present invention also provides a method for the production of adenture comprising: (i) providing a set of artificial teeth set up inlingualised occlusion according to the present invention, (ii) checkingfor acceptability of the chosen occlusal scheme, (iii) if necessary,changing to the alternate balanced occlusal scheme for the teeth bysoftening the wax or resin under the upper posterior teeth and rotatingthe upper buccal cusps downwards around the said palatal cusps on theupper teeth with such palatal cusps still remaining substantially withinthe centric stops of the lowers, and (iv) processing and finishing toproduce the denture.

Similarly, the present invention also provides a method for theproduction of a denture comprising: (i) providing a set of artificialteeth set up in balanced occlusion according to the present invention,(ii) checking for acceptability of the chosen occlusal scheme, (iii) ifnecessary, changing to the alternate lingualised occlusal scheme for theteeth by softening the wax or resin under the upper posterior teeth androtating the upper buccal cusps upwards around the said palatal cusps onthe upper teeth with such palatal cusps still remaining substantiallywithin the centric stops of the lowers, and (iv) processing andfinishing to produce the denture.

Embodiments have been described herein in a concise way. It should beappreciated that features of these embodiments may be variouslyseparated or combined within the invention.

1. A set of artificial teeth comprising a maxillary unit and amandibular unit in which, when set up in lingualised occlusion, at leastone of following occurs: the palatal cusp of the upper 4 (1) fits intothe distal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10), and wherein the buccal cusps ofthe lower teeth are out of contact with the upper teeth, such that thecusp/fossa dimensions and relationships of the teeth concerned enablethe occlusal scheme for the teeth to be changed from lingualised tobalanced occlusion simply by softening the wax or resin under the upperposterior teeth and rotating the upper buccal cusps downwards around thesaid palatal cusps on the upper teeth with such palatal cusps stillsubstantially remaining within the centric stops of the lowers.
 2. A setof artificial teeth according to claim 1, wherein at least two of thefollowing occur: the palatal cusp of the upper 4 (1) fits into thedistal fossa of the lower 4 (6), the palatal cusp of the upper 5 (2)fits into the distal fossa of the lower 5 (7), the mesial palatal cuspof the upper 6 (3) fits into the central fossa of the lower 6 (8), thedistal palatal cusp of the upper 6 (4) fits onto the marginal ridge ofthe lower 6 (9) and the mesial palatal cusp of the upper 7 (5) fits intothe central fossa of the lower 7 (10).
 3. A set of artificial teethaccording to claim 1, wherein at least three of the following occur: thepalatal cusp of the upper 4 (1) fits into the distal fossa of the lower4 (6), the palatal cusp of the upper 5 (2) fits into the distal fossa ofthe lower 5 (7), the mesial palatal cusp of the upper 6 (3) fits intothe central fossa of the lower 6 (8), the distal palatal cusp of theupper 6 (4) fits onto the marginal ridge of the lower 6 (9) and themesial palatal cusp of the upper 7 (5) fits into the central fossa ofthe lower 7 (10).
 4. A set of artificial teeth according to claim 1,wherein at least four of the following occur: the palatal cusp of theupper 4 (1) fits into the distal fossa of the lower 4 (6), the palatalcusp of the upper 5 (2) fits into the distal fossa of the lower 5 (7),the mesial palatal cusp of the upper 6 (3) fits into the central fossaof the lower 6 (8), the distal palatal cusp of the upper 6 (4) fits ontothe marginal ridge of the lower 6 (9) and the mesial palatal cusp of theupper 7 (5) fits into the central fossa of the lower 7 (10).
 5. A set ofartificial teeth according to claim 1, wherein all of the followingoccur: the palatal cusp of the upper 4 (1) fits into the distal fossa ofthe lower 4 (6), the palatal cusp of the upper 5 (2) fits into thedistal fossa of the lower 5 (7), the mesial palatal cusp of the upper 6(3) fits into the central fossa of the lower 6 (8), the distal palatalcusp of the upper 6 (4) fits onto the marginal ridge of the lower 6 (9)and the mesial palatal cusp of the upper 7 (5) fits into the centralfossa of the lower 7 (10).
 6. A set of artificial teeth comprising amaxillary unit and a mandibular unit in which, when set up in balancedocclusion, at least one of the following occurs: the palatal cusp of theupper 4 (1) fits into the distal fossa of the lower 4 (6), the palatalcusp of the upper 5 (2) fits into the distal fossa of the lower 5 (7),the mesial palatal cusp of the upper 6 (3) fits into the central fossaof the lower 6 (8), the distal palatal cusp of the upper 6 (4) fits ontothe marginal ridge of the lower 6 (9), and the mesial palatal cusp ofthe upper 7 (5) fits into the central fossa of the lower 7 (10), andwherein at least one of the buccal cusps of the lower teeth are incontact with the upper teeth, such that the cusp/fossa dimensions andrelationships of the teeth concerned enable the occlusal scheme for theteeth to be changed from balanced to lingualised occlusion simply bysoftening the wax or resin under the upper posterior teeth and rotatingthe upper buccal cusps upwards around the said palatal cusps on theupper teeth with such palatal cusps still substantially remaining withinthe centric stops of the lowers.
 7. A set of artificial teeth accordingto claim 6, wherein at least two of the following occur: the palatalcusp of the upper 4 (1) fits into the distal fossa of the lower 4 (6),the palatal cusp of the upper 5 (2) fits into the distal fossa of thelower 5 (7), the mesial palatal cusp of the upper 6 (3) fits into thecentral fossa of the lower 6 (8), the distal palatal cusp of the upper 6(4) fits onto the marginal ridge of the lower 6 (9) and the mesialpalatal cusp of the upper 7 (5) fits into the central fossa of the lower7 (10).
 8. A set of artificial teeth according to claim 6, wherein atleast three of the following occur: the palatal cusp of the upper 4 (1)fits into the distal fossa of the lower 4 (6), the palatal cusp of theupper 5 (2) fits into the distal fossa of the lower 5 (7), the mesialpalatal cusp of the upper 6 (3) fits into the central fossa of the lower6 (8), the distal palatal cusp of the upper 6 (4) fits onto the marginalridge of the lower 6 (9) and the mesial palatal cusp of the upper 7 (5)fits into the central fossa of the lower 7 (10).
 9. A set of artificialteeth according to claim 6, wherein at least four of the followingoccur: the palatal cusp of the upper 4 (1) fits into the distal fossa ofthe lower 4 (6), the palatal cusp of the upper 5 (2) fits into thedistal fossa of the lower 5 (7), the mesial palatal cusp of the upper 6(3) fits into the central fossa of the lower 6 (8), the distal palatalcusp of the upper 6 (4) fits onto the marginal ridge of the lower 6 (9)and the mesial palatal cusp of the upper 7 (5) fits into the centralfossa of the lower 7 (10).
 10. A set of artificial teeth according toclaim 6, wherein all of the following occur: the palatal cusp of theupper 4 (1) fits into the distal fossa of the lower 4 (6), the palatalcusp of the upper 5 (2) fits into the distal fossa of the lower 5 (7),the mesial palatal cusp of the upper 6 (3) fits into the central fossaof the lower 6 (8), the distal palatal cusp of the upper 6 (4) fits ontothe marginal ridge of the lower 6 (9) and the mesial palatal cusp of theupper 7 (5) fits into the central fossa of the lower 7 (10).
 11. A setof artificial teeth according to claim 6, wherein at least two, at leastthree, or at least four buccal cusps of the lower teeth are in contactwith the upper teeth.
 12. A set of artificial teeth according to claim11, wherein all of the buccal cusps of the lower teeth of the set ofartificial teeth are in contact with the upper teeth.
 13. A set ofartificial teeth according to claim 1, wherein one or more of the upperteeth have clearly defined upper palatal stamp cusps.
 14. A set ofartificial teeth according to claim 1, wherein one or more of the lowerteeth have centric stops on their occluding surfaces.
 15. A set ofartificial teeth according to claim 1, wherein each of the maxillaryunit and the mandibular unit of the set of artificial teeth comprises awax or resin base.
 16. A set of artificial teeth according to claim 1,wherein the set of artificial teeth comprises two maxillary unit andmandibular unit pairs, the units each designed for arrangement in arespective quadrant of the patient's mouth.
 17. A set of artificialteeth according to claim 1, wherein the maxillary unit comprises atleast three, or at least four maxillary posterior teeth.
 18. A set ofartificial teeth according to claim 1, wherein the mandibular unitcomprises at least three, or at least four mandibular posterior teeth.19. A set of artificial teeth according to claim 1, wherein the teethare set up in the desired occlusal scheme within denture designsoftware, and the change from lingualised to balanced occlusion or frombalanced to lingualised occlusion is performed digitally.
 20. (canceled)21. A method for the production of a denture comprising: (i) providing aset of artificial teeth set up in lingualised occlusion according toclaim 1, (ii) checking for acceptability of the chosen occlusal scheme,(iii) if necessary, changing to the alternate balanced occlusal schemefor the teeth by softening the wax or resin under the upper posteriorteeth and rotating the upper buccal cusps downwards around the saidpalatal cusps on the upper teeth with such palatal cusps stillsubstantially remaining within the centric stops of the lowers, or byperforming this step digitally, and (iv) processing and finishing toproduce the denture.
 22. A method for the production of a denturecomprising: (i) providing a set of artificial teeth set up in balancedocclusion according to claim 6, (ii) checking for acceptability of thechosen occlusal scheme, (iii) if necessary, changing to the alternatelingualised occlusal scheme for the teeth by softening the wax or resinunder the upper posterior teeth and rotating the upper buccal cuspsupwards around the said palatal cusps on the upper teeth with suchpalatal cusps still substantially remaining within the centric stops ofthe lowers, or by performing this step digitally, and (iv) processingand finishing to produce the denture.